Piston



May 5 19240 mam W. 5%. YQUNQ PISTON Filed Nov. 4, E20

Patent May 6, 392%..

WILLIAM E. YQUNG, 0F ROCKFORD, ILLINOIS.

PISTQN.

Application filed November 4, 1920. Serial No. 421,850.

One of the primary objects of this invention is to provide a superiorand more efii-' cient piston than any heretofore in use. To this end, Ihave incorporated in a piston certain principles which promotelightness, proper lubrication and greater life to the piston andcylinder. Lightness is especially desired, as it promotes kineticefiiciency and reduced the cost of production. If the piston is tooloose it soon developes what is known as piston slap, and also pumpsoil. If it fits too'tightly, it often scores and scratches the cylinderwalls, requiring reboring. By providing proper lubrication for thepiston, es ecially at the point of heaviest thrust an by securing aclose fit without seizing, the wear is reduced to a minimum and the lifeof the piston and cylinder greatly increased.

' The foregoing desiderata I have obtained, and the objections overcomeby the provision of a so-called light-wall piston, characterized by askirt portion cutaway or so shaped as to form spirally disposed ribs orveins and oil passages. This construction does not weaken the piston,but adds resiliency and strength. It also permits fitting the pistoncloser to the cylinder wall, because the perforated skirt will notbecome heated as will a solid piston, hence will not be subject toexpansion and may be fit very closely. Furthermore, this constructioninsures the delivery of a thin film of'oil over the entire cylinder walland especially at the point of heaviest thrust, and at the same timeprevents leakage past the piston.

Another object is to provide a piston having a skirt portion so shapedas to provide pockets extending substantially throughout the length ofthe skirt portion and circumscribing the same, which carry oil andlubricate thecylinder wall on the upward stroke, and on the downwardstroke wipeofi' the surplus oil and discharge it into the interior ofthe piston, where it falls to the crank case.

Still another object is to reinforce a thinwall piston in a novel mannerto obtain the desired rigidity and strength with the minimum weight.

Other objects and attendant advantages will be appreciated by thoseskilled in this art as the invention becomes better under-c stood byreference to the following description when considered in connectionwith the accompanying drawings, in which- Figure 1 is a side view of apiston embodying my invention;

Fig. a longitudinal sectional view through the piston taken on the line22 ,of Fig. 1

Fig. 3, a top view of the piston;

Fig. 4. a cross-sectional view taken on the line -1-1 of Fig. 1; and rFig. 5, a development of the piston wall on a reduced scale.

The principles of my invention may be applied to any piston for anyinternal combustion engine. although greater efficiency is obtained whenembodied in a light-wall piston. In the drawings, I have shown alightwall piston and certain features of my invention, especially asregards reinforcing,

have particular reference to this type of piston construction. Otherfeatures of my invention, however, are applicable equally as well topistons having substantially standard wall dimensions.

The piston shown in the drawings, comprises a ring body 7, head 8 and askirt which I shall refer to as comprising upper and lower portions9 and11 respectively. Suitable provision is made for carrying the wrist pin,as for example bearings 12 formed integral with the piston.

It will be observed that the skirt throughout substantially its entirelength. with the exception of the lower portion 11. is perforated or cutaway by a series of spirally disposed openings 13. The piston wallbetween these openings' constitute what I term ribs or veins, likewisespirally disposed. The upper longitudinal edges 15 of each vein and alsothe bottom edge 16 between the veins, 'are inclined to provide obtuseangles with the peripheral wall of the iston, and the lower longitudinaledges 1 and top edges 18 are inclined to provide acute angles. By reasonof this construction, the edges 15 and 16 constitute pockets which onthe up '11: ad stroke of the piston, hold oil and spread it around thecylinder wall. and the. sharper edges 17 and 18 serve on the down wardstroke, to wi e off the surplus oil, leaving only a thin fi in of oil onthe cylinder wall. It follows, therefore, that as the p stonreciprocates, it will functionto distribute oil entirely around thecylinder wall during the up stroke and remove the surplus on the downstroke, thus insuring prop y er lubrications at all points and especialat the point of heaviest thrust opposite the skirt, which reduces wearto the minimum and adds to the life of the piston and cylinder. Byperforating the skirt in the manner described, it is also possible tofit the piston closer to the cylinder walls than is possible with asolid skirt. There 1s greater resiliency in such a perforated skirt, andthe latter by reason of the relatively large openings and of the passageof Oll. and air therethrough, is kept cool and is not liable to expandand seize and wear the cylinder. In a solid wall piston, specialallowance must be made for such expansion, consequently the piston cannot be fit as closely as one of the present construction. My inventionalso contem lates a thinwall construction reinforced y spiral rlbs.

As shown in the drawings, each vein 14 is reinforced on its inner sideby a rib 19, which extends to the head 8 and is continued along theunderside thereof, these ribs 21 merging at the central portion of thehead into a ring formation 22. The ribs 19 and 21 by being spirallyarranged, distribute the weight and strength more evenly andproportionally about the piston wall and head than is possible withstraight rlbs of similar weight, and thus make possible the construc-.

tion of a relatively thin-wall, light weight piston of maximum strength.

Internal combustion engine pistons are subject to hard usage and heavstrains and stresses, as well as to extreme y high temperatures whenrunning and sometimes to extremely low temperatures when standing, withthe result that the expansion and contraction of the metal of thepistons is relativel great. With pistons as heretofore rein orced byribs and highly heated by reason of the running of the engine, thethinner portions of the walls between the ribs tend to be pressedinwardly by the exlosive force while along the lines reinforced y theribs the walls of the piston will retain their original positions,wherefore the exterior of the piston will present corners or projectionsat or alon the ribs, which corners or projections wil score grooves inthe surrounding walls of the cylinder. In the resent construction thespirally dispose ribs overlap each other circumferentially of thepiston, and even thou h the thinner walls of the piston between t e ribsmay be pressed inwardly, the reinforced portions of the walls willretain their original shape and the piston will remain circular in forminstead of becoming polygonal and of course will not score or groove thecylinder. A further advantage is secured by the present invention, inthat if the cylinder is not precisely round, the piston when heated andexpanded is capable of slight deformation from a true circle to conformto the cylinder, this being true be cause of the fact that the spiralribs are capable of slight distortion circumferentially of the cylinder.Again, the present spiral arrangement of ribs permits of the pistonbeing snugly fitted to the cylinder, when cold, so as to preclude oilleakage, and when the piston becomes expanded it is capable, by reasonof the spiral arrangement of reinforcing ribs, of a limited distortionand flexibility, which compensates for the expansion and obviatessticking or freezing to the cylinder walls.

The spiral arrangement of the ribs 21 on the under side of the pistonhead 8 is also important, as distinguished from straight radialreinforcing ribs, in that straight radial ribs elongate under the actionof heat and hence their outer ends form projections extending beyond thewalls of the piston and score the cylinder, whereas the bowed or spiralconfiguration of the present ribs prevents elongation because theexpansion under heat will cause the ribs to bulge or bow laterallyrather than elongate, and therefore whatever expansion of the headoccurs will be uniform and no rojections will result and hence scoringof tl ie cylinderis prevented.

' It will be noted that the reinforcing ribs 19 are disposed between thesuccessive openings 13 and extend along the ribs or veins between theopenings in order that each rib may be continuous from end to end of thepiston and thus compensate in strength for the material omitted byreason of the openings.

It should be understood that my invention contemplates broadly theperforating or shaping of the skirt in any suitable manner for any ofthe purposes expressed herein or inherent in the construction disclosed.

It is believed that the foregoing conveys a clear understanding of theinvention, and while I have illustrated but a single working embodiment,it should be understood that various changes might be made in theconstruction without departing from the spirit and scope of theinvention as expressed in the appended claims, in which I claim:

1. A piston whose ring-body and lower skirt portion are joined by sirally disd veins, the upper longitudina edges of which are shaped toprovide oil ockets and the lower longitudinal edges to draw the oil intothe interior of the piston.

2. A thin-wall piston having a spiral vein openings.

skirt portion and spiral ribs reinforcing said veins.

3. A thin-wall piston having a spiral vein skirt portion and spiral ribsreinforcing said veins and reaching to and extending ipirilly across theunderside of the-piston 4. A piston whose skirt portion has spirallydisposed oil passages, the lower edges and upper wall edges 0 which formobtuse angles and the top ed s and lower longitudinal edges of which ormacute angles with respect to the periphery of the iston.

5. A thin-wall piston of uniform outer diameter substantially throughoutits length, the skirt portion of said wall having a plurality ofcircumferentially spaced through openings which permit oil to splashonto the c linder wall from within the iston, the t in-wall ortionsbetween san openings being longitudinally reinforced on their innersides.

6. A thin-wall piston, the head of which is reinforced by spiral ribs.

7. A piston having a thin-wall skirt portion perforated bycircumferentially overlapping openings, and rows of reinforcin for thethin-wall portions between said i 8. A thin-wall piston, the circularwall of which is reinforced on its inside by spirally disposed ribsreachingthroughqit the skirt ortion to the head, and continuing spirallinwardly along the underside of the hea 9. A piston, the skirt portionof which is spirally perforated, the upper edges of said perforationsbeing shaped to draw the oil inwardly and the loweredges to thrust theoil outwardly.

10. A piston, the skirt rtion of which has a lurality of circumerentiall spaced throug openings, the wall along t 1e u per edge of eachopening being shaped to raw oil inwardly rom the cylinder wall, andshaped along the lower edge to thrust oil outwardly.

11. A thin-wall piston, the skirt portion of which has throughperforations of relativel lar area and is reinforced on its inside y ri5 intermediate the perforations.

12. A piston, the skirt portion of which has circumfcrentiallv spacedthrough perforations of relatively large area, allowing the oil tosplash onto the cylinder wall from the inside of the piston, saidrforations being so shaped and arranged t at the upper and lower edgesadjoining perforation, whereb on the down stroke the upper edges I drawthe oil inwardly fromt ecylinder wall throughout its circumference andon the upstroke the lower edges will spread the oilover said wall.

13. A piston having a thin-wall skirt portion having circumferentiallyspaced through openings which rmit oil to splash onto the cylinder wallsrom within the iston, and s irall dis scd rows of rein orcing for t ethin-wal portions between said openlugs.

14. A piston having a thin-wall cylindrical body provided on its innerside with reinforcing ribs inclined lon 'tudinall and overlappingcircumferentiafl y where y to prevent flattening of the thin-wall bodybetween the ribs due to the side thrust imposed on the piston.

15. A hollow piston, comprisinga head and side wall, the inner surfacesof the head and side wall having a series of reinforcing ribs formedcontinuously spiral relative to the head and side wall.

16. A hollow piston, comprising a head and side wall formed on the innersurfaces thereof with reinforcing ribs arran ed continuously spiral withrespect to t 1e head and side wall, the ribs on the side walloverlapping in vertical planes.

17. A hollow iston, comprising a head and side wall, t latter havinginwardly extended hollow wrist in bosses, integral ribs formed on thehead and side wall, the ribs on the head portion being spirally arrangedand merging into s irally arranged rib ortions on the side wa l, thelatter rib portion intersecting the bosses.

18. A hollow piston including a head and side wall, and a series ofreinforcin ribs, each continuous from the central ortion of the head tothe lower rtion o the side wall, each rib being spiral with respect tothe radial line of the head and also s iral with respect to the verticalplane 0 the side wal WILLIAM K. YOUNG.

of each perforation cir-...v cumferentially overlaps of the next

